[ NNSquad ] Re: Catalog of Measurement Tools

[Kevin McArthur <kevin@stormtide.ca>]

It will also allow you to send a payload and get a latency reading from each hop.

Running this test to the same recipient host, on multiple ports, will expose port-based throttling very quickly as your latency figures will drop drastically when you hit the throttling hop on the throttled port. These tests are also easily repeated to allow for varience in network quality.

I'd also point out it is good to take a statistical approach with all these tools to measure throttling over time. A reading like VoIP packets were observed to be 23% slower on average over the period of a week with a 5 minute testing interval can be highly relied upon and will tend to eliminate sources of error like the src and dst system loads, or the state of a network router at any given time.

K

The Anarcat wrote:

On Tue, Nov 13, 2007 at 03:19:12PM -0800, Kevin McArthur wrote:
  

tcptraceroute is probably the most useful tool for detecting tcp port 
interference.
    

Well, it depends what *kind* of intereference. If you want to test
throttling, it won't do no good, and netcat/netrw might be of better
help there. If you want to test openness, might as well use nmap, as it
can very rapidly test which ports are blocked.

traceroute is useful to diagnose *where* and why the port is blocked.

A.